@@ -505,15 +505,22 @@ static void
mt7915_mcu_tx_rate_report(struct mt7915_dev *dev, struct sk_buff *skb)
{
struct mt7915_mcu_ra_info *ra = (struct mt7915_mcu_ra_info *)skb->data;
- u16 wcidx = le16_to_cpu(ra->wlan_idx);
- struct mt76_wcid *wcid = rcu_dereference(dev->mt76.wcid[wcidx]);
- struct mt7915_sta *msta = container_of(wcid, struct mt7915_sta, wcid);
- struct mt7915_sta_stats *stats = &msta->stats;
- struct mt76_phy *mphy = &dev->mphy;
struct rate_info rate = {}, prob_rate = {};
+ u16 probe = le16_to_cpu(ra->prob_up_rate);
u16 attempts = le16_to_cpu(ra->attempts);
u16 curr = le16_to_cpu(ra->curr_rate);
- u16 probe = le16_to_cpu(ra->prob_up_rate);
+ u16 wcidx = le16_to_cpu(ra->wlan_idx);
+ struct mt76_phy *mphy = &dev->mphy;
+ struct mt7915_sta_stats *stats;
+ struct mt7915_sta *msta;
+ struct mt76_wcid *wcid;
+
+ if (wcidx >= MT76_N_WCIDS)
+ return;
+
+ wcid = rcu_dereference(dev->mt76.wcid[wcidx]);
+ msta = container_of(wcid, struct mt7915_sta, wcid);
+ stats = &msta->stats;
if (msta->wcid.ext_phy && dev->mt76.phy2)
mphy = dev->mt76.phy2;
Smatch complains that "wcidx" value comes from the network and thus cannot be trusted. In this case, it actually seems to come from the firmware. If your wireless firmware is malicious then probably no amount of carefulness can protect you. On the other hand, these days we still try to check the firmware as much as possible. Verifying that the index is within bounds will silence a static checker warning. And it's harmless and a good exercise in kernel hardening. So I suggest that we do add a bounds check. Fixes: e57b7901469f ("mt76: add mac80211 driver for MT7915 PCIe-based chipsets") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> --- v2: Fix a typos in commit message. Normally for networking patches, when we change the declaration block, we must update the order to make sure it's in reverse Christmas tree format. This code wasn't strictly in reverse Christmas tree order originally because we needed to initialize "wcidx" before we could initialize "wcid" etc. Re-ordering the initializers makes the diff slightly larger than people might expect but it's a required part of networking patches. .../net/wireless/mediatek/mt76/mt7915/mcu.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-)